• Considering user aspects improves task-oriented dialogue performance • Large language models adapt to user aspects; small models lack aspectawareness • Large language models generate synthetic aspect-specific dialogues for distillation • Aspect-aware capabilities distilled from large to small language models Research on developing dialogue systems with large language models (LLMs) has been extensive, relying heavily on LLMs’ capabilities to generate contextually nuanced responses. Yet, these approaches are not easily transferable to smaller language models (sLMs), particularly in task-oriented dialogue (ToD) scenarios, where dialogue systems are required to engage in personalized interactions with humans. In this paper, we investigate LLM distillation approaches for sLM-based ToD systems and present an Aspect-Augmented Dialogue Distillation (A2D2) framework, aiming to compress the human aspect-aware capabilities of an LLM into an sLM while ensuring the fulfillment on task specific requirements. The framework incorporates a set of human aspects individually into LLM-based ToD data generation to improve the effectiveness and efficiency of the LLM-to-sLM distillation process, thereby establishing robust sLM-based ToD systems that are adaptable to diverse users and achieving higher task success rates. We demonstrate that the sLM-based ToD systems derived through A2D2 yield competitive performance on various ToD scenarios including unseen task settings, adapting to a wide range of synthetic users characterized by multiple aspects.

Federated Learning (FL) is a promising technique for edge computing environments as it provides better data privacy protection. It enables each edge node in the system to send a central server a computed value, named gradient, rather than sending raw data. However, recent research results show that the FL is still vulnerable to an inference attack, which is an adversarial algorithm that is capable of identifying the data used to compute the gradient. One prevalent mitigation strategy is differential privacy which computes a gradient with noised data, but this causes another problem that is accuracy degradation. To effectively deal with this problem, this paper proposes a new digestive neural network (DNN) and integrates it into FL. The proposed scheme distorts raw data by DNN to make it unrecognizable then computes a gradient by a classification network. The gradients generated by edge nodes will be sent to the server to complete a trained model. The simulation results show that the proposed scheme has 9.31% higher classification accuracy and 19.25% lower attack accuracy on average than the differential private schemes.

Federated Learning (FL) is an efficient and secure machine learning technique designed for decentralized computing systems such as fog and edge computing. Its learning process employs frequent communications as the participating local devices send updates, either gradients or parameters of their models, to a central server that aggregates them and redistributes new weights to the devices. In FL, private data does not leave the individual local devices, and thus, rendered as a robust solution in terms of privacy preservation. However, the recently introduced membership inference attacks pose a critical threat to the impeccability of FL mechanisms. By eavesdropping only on the updates transferring to the center server, these attacks can recover the private data of a local device. A prevalent solution against such attacks is the differential privacy scheme that augments a sufficient amount of noise to each update to hinder the recovering process. However, it suffers from a significant sacrifice in the classification accuracy of the FL. To effectively alleviate the problem, this paper proposes a Digestive Neural Network (DNN), an independent neural network attached to the FL. The private data owned by each device will pass through the DNN and then train the FL. The DNN modifies the input data, which results in distorting updates, in a way to maximize the classification accuracy of FL while the accuracy of inference attacks is minimized. Our simulation result shows that the proposed DNN shows significant performance on both gradient sharing- and weight sharing-based FL mechanisms. For the gradient sharing, the DNN achieved higher classification accuracy by 16.17% while 9% lower attack accuracy than the existing differential privacy schemes. For the weight sharing FL scheme, the DNN achieved at most 46.68% lower attack success rate with 3% higher classification accuracy.

MPEG-DASH is a video streaming standard that outlines protocols for sending audio and video content from a server to a client over HTTP. However, it creates an opportunity for an adversary to invade users’ privacy. While a user is watching a video, information is leaked in the form of meta-data, the size of data and the time the server sent the data to the user. After a fingerprint of this data is created, the adversary can use this to identify whether a target user is watching the corresponding video. Only one defense strategy has been proposed to deal with this problem: differential privacy that adds sufficient noise in order to muddle the attacks. However, that strategy still suffers from the trade-off between privacy and efficiency. This paper proposes a novel defense strategy against the attacks with rigorous privacy and performance goals creating a private, scalable solution. Our algorithm, “No Data are Alone” (NDA), is highly efficient. The experimental results show that our scheme is more than two times efficient in terms of excess downloaded video (represented as waste) compared to the most efficient differential privacy-based scheme. Additionally, no classifier can achieve an accuracy above 7.07% against videos obfuscated with our scheme.

Vehicle to everything (V2X) in heterogeneous networks concurrently retains multiple communication links within a channel: such as vehicle to vehicle (V2V), Vehicle to macro base station (V2C), and cellular user equipment to femtocell base station (U2F). To provide high spectral efficiency, there were many efforts such as non-orthogonal multiple access (NOMA) and channel aggregation. However, combining these schemes on the top of NOMA-V2X-femtocell is extremely challenging as it increases the number of dimensions to be considered. To address this issue, this paper proposes a new genetic deep learning algorithm. It employs a genetic algorithm (GA) to find a pair of communication links per channel in a way to maximize the throughput and a neural network to reduce the dimension gradually. The neural network is trained to predicts which pair can be part of the final result. The suitable pairs are marked by deep learning, then they are not shuffled in the subsequent generations. The simulation results show that the proposed scheme achieved higher throughput greater than 20%, compared to the existing GA.

Network anomalies are correlated to activities that deviate from regular behavior patterns in a network, and they are undetectable until their actions are defined as malicious. Current work in network anomaly detection includes network-based and host-based intrusion detection systems. However, most of them suffer from high false detection rates due to the base rate fallacy. To overcome such a drawback, this paper proposes a superior behavior-based anomaly detection system (SuperB) that defines legitimate network behaviors of authorized users in order to identify unauthorized accesses. We define the network behaviors of the authorized users by training the proposed deep learning model with time-series data extracted from network packets of each of the users. Then, the trained model is used to classify all other behaviors (we define these as anomalies) from the defined legitimate behaviors. As a result, SuperB effectively detects all anomalies of network behaviors. Our simulation results show that the proposed algorithm needs at least five end-to-end conversations to achieve over 95% accuracy and over 93% recall rate. Some simulations show 100% accuracy and recall rate. Our simulations use live network data combined with the CICIDS2017 data set. The performance has an average of less than 1.1% false-positive rate with some simulations showing 0%. The execution time to process each conversation is 85.20±0.60 milliseconds (ms), and thus it takes about only 426 ms to process five conversations to identify anomaly.

This paper proposes a MAC protocol for Radio Frequency (RF) energy harvesting in Wireless Sensor Networks (WSN). In the conventional RF energy harvesting methods, an Energy Transmitter (ET) operates in a passive manner. An ET transmits RF energy signals only when a sensor with depleted energy sends a Request-for-Energy (RFE) message. Unlike the conventional methods, an ET in the proposed scheme can actively send RF energy signals without RFE messages. An ET determines the active energy signal transmission according to the consequence of the passive energy harvesting procedures. To transmit RF energy signals without request from sensors, the ET participates in a contention-based channel access procedure. Once the ET successfully acquires the channel, it sends RF energy signals on the acquired channel during Short Charging Time (SCT). The proposed scheme determines the length of SCT to minimize the interruption of data communication. We compare the performance of the proposed protocol with RF-MAC protocol by simulation. The simulation results show that the proposed protocol can increase the energy harvesting rate by 150% with 8% loss of network throughput compared to RF-MAC. In addition, the proposed protocol can increase the lifetime of WSN because of the active energy signal transmission method.